DISCLAIMER: PW's dosage information is gathered from users and resources for educational purposes only. It is not a recommendation and should be verified with other sources for accuracy.

Alpha-GPC (alpha-glycerophosphocholine, choline alfoscerate) is a water-soluble nutrient which serves as a precursor to both choline and glycerophosphate within the brain. In humans, choline is considered to be an essential nutrient as its role in reducing the risk of neural tube defects, fatty liver disease, and other pathologies has been well-documented.[1]

Notably, alpha-GPC is one of the three choline-containing phospholipids that can be orally supplemented (the other two being citicoline and phosphatidylcholine) and its popularity may be due to it being the most efficient pro-drug of choline (with the ability to influence both systemic and brain concentrations of choline). Due to the provision of the other half of the alpha-GPC molecule (glycerophosphate), it also appears to support the structure and maintenance of cellular membranes, similarly to citicoline.

Athletes have been known to use alpha-GPC due to its purported ability to enhance growth hormone production and to enhance power output (which is based on a lone pilot study in support of subjects ingesting 600 mg alpha-GPC prior to exercise[2]).

When taken as a supplement, this compound has nootropic effects which may have the potential for the treatment of Alzheimer's disease[3] and other related disorders.[4] It is easily available and commonly sold for this purpose via online supplement and nootropic vendors.

Chemistry

Alpha-GPC is a naturally-occurring choline compound found endogenously (naturally) in the brain which is also made and used for oral consumption. Structurally, Alpha-GPC is comprised of a choline group bound to a glycerol molecule via a phosphate group.

Choline is a quaternary ammonium salt, containing a positively charged ammonium cation substituted with three methyl groups and a hydroxyethyl chain. Glycerol is a polysubstituted alcohol consisting of propane with one hydroxyl (-OH) group bound to each carbon in the chain.

In alpha-GPC, the terminal oxygen of the choline chain and a primary hydroxyl group of glycerol are integrated as bridging oxygen into a phosphate group. This phosphate group is a quaternary-substituted phosphorus atom connected to four oxygen atoms, two of which serve to bind the choline, glycerol, and phosphate groups into a unified molecule.

Pharmacology

Alpha-GPC breaks down into two key components, choline and glycerophosphate.
Choline and its metabolites are needed for three main physiological purposes: structural integrity and signaling roles for cell membranes as well as cholinergic neurotransmission (acetylcholine synthesis).[5] This process essentially allows acetylcholine to accumulate at higher levels than it otherwise would. As acetylcholine is involved in the function of memory and other essential cognitive functions, this could potentially account for its nootropic effects.

Glycerophosphate, the other component, can also help with the production of cellular membranes, but this remains largely unstudied and is not well understood by the scientific literature.

Subjective effects

The effects listed below are based upon the subjective effects index and personal experiences of PsychonautWikicontributors. The listed effects should be taken with a grain of salt and will rarely (if ever) occur all at once, but heavier doses will increase the chances and are more likely to induce a full range of effects. Likewise, adverse effects become much more likely on higher doses and may include serious injury or death.

Physical effects

Body odor alteration - This can be caused in some populations, especially those suffering from trimethylaminuria. Choline (a byproduct of alpha-GPC) is a precursor to trimethylamine, which those with trimethylaminuria are not able to easily break down, oftening resulting in smelling similar to fish.

Cognitive effects

Wakefulness - In comparison to citicoline, alpha-GPC manifests itself primarily in a physically stimulating manner over a mental stimulation.

Toxicity and harm potential

Alpha-GPC is non-addictive, is not known to cause harm, and has an extremely low toxicity relative to dose. Similar to many other nootropic substances, there are relatively few physical side effects associated with acute choline exposure. Various studies have shown that in reasonable doses in a particular context, it presents no negative cognitive, psychiatric or toxic physical consequences of any sort.

Regardless, it is strongly recommended that one is familiar with and uses harm reduction practices when using this substance.

Tolerance and addiction potential

Alpha-GPC is not habit-forming and the desire to use it can actually decrease with use. It is most often self-regulating.

Tolerance to the effects of alpha-GPC is built after prolonged and repeated usage. After that, it takes about 7 days for the tolerance to be reduced to half and 14 days to be back at baseline (in the absence of further consumption). Alpha-GPC presents cross-tolerance with no other known compounds, meaning that after the use of Alpha-GPC all other psychoactive compounds will not have a reduced effect.